It's a logo of a nut in the shape of an acorn. It has a shell with a cap on it as well as the stem on the top that the nut would hang from a tree from.
This Nut icon has Android KitKat style
. If you use the icons for Android apps, we recommend using our latest Material Icons icon pack (please check our sidebar on the right). Otherwise, it's a solid icon pack that looks good in small resolutions, either on the web or in print. It's characterized by thick lines, smooth corners, and is optimized for 24x24 pixels.